How load to Django Paginator Page (next/ previous)? - django

Question

Hy,
i followed a tutorial for a multiple model search and it worked. now i want to paginate the output. But how can i load my paginator page (next/ previous) data into my template? So far if i push next i get an error.
views.py
from django.views.generic import TemplateView, ListView
from django.views.generic import View
from django.shortcuts import render
from django.db.models import Q
from django.core.paginator import Paginator
from itertools import chain
# --- Import Models
from datainput.models import Animal
from datainput.models import Farmer
<....>
class SearchView(ListView):
template_name = 'farmapi/searchview.html'
paginate_by = 2
count = 0
def get_context_data(self, *args, **kwargs):
context = super().get_context_data(*args, **kwargs)
context['count'] = self.count or 0
context['query'] = self.request.GET.get('q')
return context
def get_queryset(self):
request = self.request
query = request.GET.get('q', None)
if query is not None:
farmer_results = Farmer.objects.search(query)
animal_results = Animal.objects.search(query)
# combine querysets
queryset_chain = chain(
farmer_results,
animal_results
)
qs = sorted(queryset_chain,
key=lambda instance: instance.pk,
reverse=True)
self.count = len(qs) # since qs is actually a list
return qs
return Farmer.objects.none() # just an empty queryset as default
template.html
{% extends 'base.html' %}
{% load class_name %}
{% load static %}
{% block custom_css %}
<link rel="stylesheet" type="text/css" href="{% static 'css/home_styles.css' %}">
{% endblock %}
{% block content %}
<div style="height: 10px;">
</div>
<div class="container-fluid">
<div class='row'>
<div class="col-4 offset-md-8">
<form method='GET' class='' action='.'>
<div class="input-group form-group-no-border mx-auto" style="margin-bottom: 0px; font-size: 32px;">
<span class="input-group-addon cfe-nav" style='color:#000'>
<i class="fa fa-search" aria-hidden="true"></i>
</span>
<input type="text" name="q" data-toggle="popover" data-placement="bottom" data-content="Press enter to search" class="form-control cfe-nav mt-0 py-3" placeholder="Search..." value="" style="" data-original-title="" title="" autofocus="autofocus">
</div>
</form>
</div>
</div>
</div>
<div style="height: 10px;">
</div>
<div class="container-fluid">
<div class="row">
<div class="col-6 offset-md-4">
{% for object in object_list %}
{% with object|class_name as klass %}
{% if klass == 'Farmer' %}
<div class='row'>
Farmer: <a href='{{ object.get_absolute_url }}'> {{ object.first_name }} {{ object.last_name }}</a>
</div>
{% elif klass == 'Animal' %}
<div class='row'>
Animal: <a href='{{ object.get_absolute_url }}'> {{ object.name }} {{ object.species }}</a>
</div>
{% else %}
<div class='row'>
<a href='{{ object.get_absolute_url }}'>{{ object }} | {{ object|class_name }}</a>
</div>
{% endif %}
{% endwith %}
{% empty %}
{% endfor %}
<div style="height: 10px;">
</div>
<div class='row'>
<results>{{ count }} results for <b>{{ query }}</b></results>
</div>
</div>
</div>
</div>
<div class="container-fluid">
<!-- Pagniator Data -->
<div class="paginator">
<span class="step-links">
<span class="current">
Page {{ page_obj.number }} of {{ page_obj.paginator.num_pages }}.
</span>
{% if page_obj.has_previous %}
« first
previous
{% endif %}
{% if page_obj.has_next %}
next
last »
{% endif %}
</span>
</div>
</div>
{% endblock %}
if i my template shows me for instance "4 Results for xyz" and "Page 1 of 2" and i push next or last Page, then i get this Error Message:
Page not found (404) Request Method: GET Request URL:
http://127.0.0.1:8000/data/searchview/?page=2 Raised by:
farmapi.views.SearchView
Invalid page (2): That page contains no results
So as far as i understand i have to explicit paginate the return of my queryset so that the paginator will put it into? Or did i miss to set a request for the paginator?

Answer 1

I also use a paginator where the number of items per page can be defined by the user. I added following method:
def get_paginate_by(self, queryset):
limit = int(self.request.POST.get('limit', 25))
return limit
In the template it looks like:
{% if is_paginated %}
{{ page_obj|render_paginator }}
{% endif %}
where render_paginator a template tag is.
In your template call a url like: your_url?page=2